Question

A particle with specific charge $\alpha$, enters a magnetic field of magnitude B, existing only to the right of the boundary YZ, as shown. The direction of motion of the particle is perpendicular to the direction of B. If the time spent by the particle in the field is K × $\frac{\pi}{3\alpha B}$, find the value of 'K'

Answer 1

K = 1

Answer 2

The particle follows a circular arc subtending an angle of $\pi/3$. With angular speed $\omega = \alpha B$, time = $(\pi/3)/(\alpha B) = \pi/(3\alpha B)$, hence K = 1.